| 摘要 |
PURPOSE:To accomplish a highly accurate measurement of oxigen concentration by closing the gas passage for introducing exhaust gas to the exposed surface of a detecting element with a porous protective layer existing independently of the reaction electrode. CONSTITUTION:A protective layer 47 is composed of a porous layer formed in the shape of a disc. This protective layer 47 is arranged between an exhaust gas introducing port 44a cut on a sheath 44 and a reaction electrode 42 having one side thereof adhering to the reaction electrode 42 while the other side adheres to the bottom side of the sheath 44 closing the exhaust gas introducing port with an aid of the pressure welding force imparted to the detecting element 41. The thickness of the protective layer 47 is so determined that the exhaust gas can evenly reach the exposed surface of the detecting element 41 passing through the protective layer 47 and the reaction electrode 42. This allows the measurement of oxygen concentration with a high accuracy. |
